Skip to main content

Astronomers create most accurate map yet of all the matter in the universe

Of all the questions facing astronomers today, some of the biggest unknowns are about the stuff that makes up most of the universe. We know that the ordinary matter we see all around us makes up just 5% of all that exists, while the rest is made up of dark matter and dark energy. But because dark matter doesn’t interact with light, it is extremely hard to study — we have to infer its existence and position from looking at the way it interacts with the ordinary matter around it.

The Blanco Telescope dome at the Cerro Tololo Inter-American Observatory in Chile, where the Dark Energy Camera used for the recently completed Dark Energy Survey was housed.
The Victor M. Blanco Telescope dome at the Cerro Tololo Inter-American Observatory in Chile, where the Dark Energy Camera used for the recently completed Dark Energy Survey is housed. Reidar Hahn, Fermilab

Recent research is helping in this task by producing the most accurate map to date of how both matter and dark matter are spread across the universe. Astronomers collected information from two different telescopes, the Dark Energy Survey telescope and the South Pole Telescope, to make their map as precise as possible.

Recommended Videos

For both telescope data sets, the researchers used the phenomenon of gravitational lensing — in which a massive body like a star, galaxy, or galaxy cluster warps spacetime and acts like a magnifying glass — to detect both regular matter and dark matter.

By comparing maps of the sky from the Dark Energy Survey telescope (at left) with data from the South Pole Telescope and the Planck satellite (at right), the team could infer how the matter is distributed.
By comparing maps of the sky from the Dark Energy Survey telescope ( from left) with data from the South Pole Telescope and the Planck satellite, the team could infer how the matter is distributed. Yuuki Omori

The results brought some surprises, like the fact that matter is less clumpy than would be expected based on current models of how the universe formed. It shows that the matter is more evenly spread out that predicted. If other surveys find similar results, this could indicate that there is something missing from current theories on how the universe formed in the period immediately following the Big Bang.

Please enable Javascript to view this content

“I think this exercise showed both the challenges and benefits of doing these kinds of analyses,” said one of the lead authors of the research, Chihway Chang of the University of Chicago, in a statement. “There’s a lot of new things you can do when you combine these different angles of looking at the universe.”

The research is published in three papers in the journal Physical Review D.

Georgina Torbet
Georgina has been the space writer at Digital Trends space writer for six years, covering human space exploration, planetary…
Euclid mission launches to probe the mysteries of dark matter
This artist’s concept shows the ESA (European Space Agency) Euclid mission in space.

The European Space Agency (ESA) has successfully launched its Euclid space telescope to study the mysteries of dark matter and dark energy. The spacecraft launched from Cape Canaveral in Florida using a SpaceX Falcon 9 rocket, with liftoff at 11:12 a.m. ET (8:12 a.m. PT).

This artist’s concept shows the ESA (European Space Agency) Euclid mission in space. ESA, CC BY-SA 3.0 IGO

Read more
How to watch the Euclid dark matter telescope launch this Saturday
This artist impression shows Euclid leaving Earth and on its way to Sun-Earth Lagrange point L2. This equilibrium point of the Sun-Earth system is located 1.5 million kilometres from Earth in the opposite direction of the Sun. L2 revolves around the Sun along with Earth. During Euclid’s orbit at L2, Euclid’s sunshield always blocks the light from the Sun, Earth and Moon while pointing its telescope towards deep space, ensuring a high level of stability for its instruments.

The astronomy community is about to get a new instrument to probe the mysteries of dark matter, with the launch of the European Space Agency (ESA)'s Euclid telescope this Saturday. Euclid is a highly sophisticated space-based telescope that will observe huge swaths of the sky to create a 3D model of the universe to help elucidate some of the biggest questions in cosmology.

Euclid | Journey to darkness

Read more
This one instrument has surveyed 2 million objects to understand dark energy
The Dark Energy Spectroscopic Instrument (DESI) making observations in the night sky on the Nicholas U. Mayall 4-meter Telescope at Kitt Peak National Observatory in Arizona.

The vastness of the universe is hard to comprehend, let alone map, but a cosmological project from the National Science Foundation's NOIRLab aims to do just that. The Dark Energy Spectroscopic Instrument (DESI) is designed to create a 3D map of millions of astronomical objects, and an early release of data from the project combines the thousands of exposures taken by the instrument during its validation phase in 2020 and 2021. It contains nearly 2 million objects.

The video below shows part of the survey validation data, with detailed portions of the sky shown in 20 different directions. Each "beam" of light is one part of the data, showing objects like stars, galaxies, and quasars. There are over 700,000 objects in this 3D map, and as impressive as that is, this represents just 1% of the total volume that will be mapped out in the DESI survey.

Read more